1. Field of the Invention
The present invention relates to tools for working tubular conduits or pipes, and more particularly to a tool which forms an outwardly projecting ridge in pipes. The tool is employed in fabrication applications wherein purely tubular stock must be modified to include a ridge. Pipes which are intended to be assembled to form fluid conducting assemblies which are to receive fittings which rely on interference with the their associated pipes are afforded such interference by a ridge formed by the novel tool. The novel tool finds application in the fields of construction of plumbing systems, fire sprinkler systems, heating and cooling piping systems, and other residential, industrial, commercial, military, and institutional construction projects wherein interference based fittings are to be incorporated and tubular stock piping is utilized.
2. Description of the Prior Art
Buildings greater than those for single family residences may have involved piping systems wherein pipes extend along ceilings and floors quite extensively. A principal example is that of fire sprinkler systems, which may be either wet or dry. During construction of typical commercial, multi-unit residential, multi-use, institutional, industrial, and military buildings, fire sprinkler systems are installed after the structural elements of the building are erected, and prior to finishing the building. For example, a sprinkler system is assembled prior to installation of dropped ceilings.
Fabrication of a sprinkler system or other large scale fluid distribution system is difficult since pipe is ordinarily furnished in awkward lengths that are not easily maneuvered into place. In a typical building, sprinkler and other piping systems must compete for space with electrical components, duct work for heating, ventilation, and air conditioning (HVAC) systems, structural elements which may project from floor slabs, ceilings, and columns, communications cables, and other architectural or functional features. A mechanic fitting pipes together may find that access, if not completely obstructed, is limited. This situation is frequently encountered in commercial construction projects.
One development which addresses this difficulty is that of utilizing fittings and connectors which are slipped axially over exposed ends of pipe, then locked to the pipe. An example is seen in Application Ser. No. 08/984,045, now U.S. Pat. No. 6,056,330, filed Dec. 3, 1997 by the present inventor and James R. Drury, a co-inventor of the aforementioned application. The filed application is directed to axially clamping pipe couplers of the type which require an outwardly projecting ridge formed in a pipe receiving a coupler. This application is hereby incorporated by reference.
Pipe may have an outwardly projecting ridge (hereinafter referred to as "ridge") formed therein by a suitable rolling tool of the type more typically employed to form an inwardly projecting groove. Tools for forming a ridge by rolling a pipe are known. Examples are seen in U.S. Pat. No. 2,809,687, issued to William Jackson Ogle on Oct. 15, 1957, and U.S. Pat. No. 4,790,166, issued to Richard A. Kaar on Dec. 13, 1988. These prior art devices are self-contained tools none of which is adapted to form a readily deployed accessory mounted on a pipe working machine. By contrast, the present invention provides a carriage configured to enable the ridge forming accessory to be readily swung out of the way to allow other pipe working operations to proceed when desired.
U.S. Pat. No. 718,830, issued to William W. Doolittle on Jan. 20, 1903, sets forth a pipe truing device which operates by rolling pipe against rollers. However, unlike the present invention, the rollers are not disposed to be able to form a ridge in the pipe in the manner of the present invention. Also, the device of Doolittle is not readily mounted on a multipurpose, powered pipe working machine, as is the present invention.
Prior art tools which are pivotally mounted on support rails of the powered chuck of a multipurpose pipe working machine are known, as exemplified by U.S. Pat. No. 5,079,940, issued to Dale A. Pulver et al. on Jan. 14, 1992. However, the tool of Pulver et al. does not form an outwardly projecting ridge in the manner of the present invention, and also only loosely engages its host machine, whereas the present invention allows for secure retention on the host machine. Notably, the tool of Pulver et al. cannot be retained on the host machine in a standby position, as can the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.